Make email optin embed full-width?

If you scroll to the bottom of this page (https://agentrosehq.com/never-alone-short-story/), you can see that the embed is not full-width, it always appears as a box with white space at the sides. How can I design a full-width email optin?

For example, something like this at the top of this site’s page: https://www.almostzerowaste.com/

• This topic was modified 4 years, 3 months ago by agentrosehq.

The page I need help with: [log in to see the link]